Conference Agenda & Scheduling

View All Sessions My Itinerary Lunches
Filter by
Print Itinerary PDF Agenda Presentations
Search found 1 results for: "TU-F2"
Session
ADDRESSING PROBLEMATIC VOCS IN VI EVALUATIONS AND MITIGATION    TU-F2
Tuesday     10am to 11:30am
Room GOLD KEY I/II
Seating104 of 108 seats available
CreditsREHS: 1.5  
SpeakersGina Plantz, Bart Eklund, Catherine Regan
ObjectiveThis session summarizes lessons learned over the last 20 years in evaluating potential VI of problematic VOCs.
DescriptionThe primary risk drivers in vapor intrusion (VI) studies almost always are tetrachloroethylene (PCE), trichloroethylene (TCE), benzene, or some fraction of total petroleum hydrocarbons (TPH). Nonetheless, decisions about further testing or mitigation may be driven by exceedances of screening levels of numerous other volatile organic compounds (VOCs). VI guidance in California includes screening levels for over 150 compounds. These extended lists of screening levels include various compounds that have proven to be problematic in past VI investigations due to their detection in shallow soil vapor and/or indoor air at sites where they are not undergoing vapor intrusion. Some compounds of particular interest are: 1,3-butadiene, acrolein, carbon tetrachloride, chloroform, 1,4-dichlorobenzene, and vinyl chloride. This session summarizes lessons learned over the last 20 years in evaluating potential VI of these problematic compounds. The fate & transport of these compounds has been investigated and they (almost) always have been found to not pose a VI risk at a given site. The lessons learned vary from compound to compound. Some compounds (e.g., 1,3-butadiene) have a very short half-life and therefore would not be expected to survive in soil gas long enough to pose a VI risk. Some compounds (e.g., acrolein) have been demonstrated to be false positives in evacuated, stainless-steel canisters. Carbon tetrachloride is found in outdoor air at or above screening levels, and infiltration of outdoor air into buildings results in potential exceedances indoors. Chloroform is a trihalomethane and typically is introduced into buildings via chlorinated municipal water supplies. 1,4-dichlorobenzene is a carcinogen found at concentrations above conservative screening levels in industrial and public buildings due to its use in cleaning products such as urinal cakes. Vinyl chloride is readily biodegraded in the presence of oxygen, so while it may be present at depth at a given site, it generally is absent in shallow soil gas. . Additionally, this session will present considerations for developing VI mitigation system operation, maintenance and monitoring programs. The same problematic VOCs summarized above can be challenges in evaluating the effectiveness of VI mitigation systems. The VI mitigation system should be operated with your site conceptual model in mind, not only when it is chosen, designed and installed but also when it is operated over the short and long term. For example, soil vapor probes may be kept in place and sampled if decreased concentrations of the vapor plume may trigger an evaluation to shut down the system. This session will also discuss other data to evaluate system performance like vacuum, flow and differential pressure may be collected on a quarterly, semi-annual or annual basis depending on site specific objectives.
Since we will be using our calcupa.org "My Itinerary" process for the 2025 Conference for Attendees to Earn CEUs, please create your Itinerary by going to the online agenda and clicking on the "+Add" button on the right of the page to Add Sessions you plan to attend to your "My Itinerary".  To View/Edit your Itinerary for Session Attendance, visit your My Itinerary.  We will provide further information on how to 'check in/out' of a Session to verify your attendance. If you have any questions, please email registration@calcupa.org.